ref: e2cea92259ab384150ee7056695db359745f9987
dir: /zelda_cpu_infra.c/
// This file handles running zelda through the emulated cpu.
// It defines the runtime environment for the emulated side-by-side state.
// It should be possible to build and run the game without this file
#include "zelda_cpu_infra.h"
#include "zelda_rtl.h"
#include "variables.h"
#include "spc_player.h"
#include "snes/snes.h"
#include "snes/snes_regs.h"
#include "snes/cpu.h"
#include "snes/cart.h"
#include "snes/tracing.h"
Snes *g_snes;
Cpu *g_cpu;
uint8 g_emulated_ram[0x20000];
static void PatchRom(uint8 *rom);
uint8 *GetPtr(uint32 addr) {
Cart *cart = g_snes->cart;
return &cart->rom[(((addr >> 16) << 15) | (addr & 0x7fff)) & (cart->romSize - 1)];
}
uint8 *GetCartRamPtr(uint32 addr) {
Cart *cart = g_snes->cart;
return &cart->ram[addr];
}
typedef struct Snapshot {
uint16 a, x, y, sp, dp, pc;
uint8 k, db, flags;
uint8 ram[0x20000];
uint16 vram[0x8000];
uint16 sram[0x2000];
} Snapshot;
static Snapshot g_snapshot_mine, g_snapshot_theirs, g_snapshot_before;
static void MakeSnapshot(Snapshot *s) {
Cpu *c = g_cpu;
s->a = c->a, s->x = c->x, s->y = c->y;
s->sp = c->sp, s->dp = c->dp, s->db = c->db;
s->pc = c->pc, s->k = c->k;
s->flags = cpu_getFlags(c);
memcpy(s->ram, g_snes->ram, 0x20000);
memcpy(s->sram, g_snes->cart->ram, g_snes->cart->ramSize);
memcpy(s->vram, g_snes->ppu->vram, sizeof(uint16) * 0x8000);
}
static void MakeMySnapshot(Snapshot *s) {
memcpy(s->ram, g_zenv.ram, 0x20000);
memcpy(s->sram, g_zenv.sram, 0x2000);
memcpy(s->vram, g_zenv.ppu->vram, sizeof(uint16) * 0x8000);
}
static void RestoreMySnapshot(Snapshot *s) {
memcpy(g_zenv.ram, s->ram, 0x20000);
memcpy(g_zenv.sram, s->sram, 0x2000);
memcpy(g_zenv.ppu->vram, s->vram, sizeof(uint16) * 0x8000);
}
static void RestoreSnapshot(Snapshot *s) {
Cpu *c = g_cpu;
c->a = s->a, c->x = s->x, c->y = s->y;
c->sp = s->sp, c->dp = s->dp, c->db = s->db;
c->pc = s->pc, c->k = s->k;
cpu_setFlags(c, s->flags);
memcpy(g_snes->ram, s->ram, 0x20000);
memcpy(g_snes->cart->ram, s->sram, g_snes->cart->ramSize);
memcpy(g_snes->ppu->vram, s->vram, sizeof(uint16) * 0x8000);
}
static bool g_fail;
// b is mine, a is theirs
static void VerifySnapshotsEq(Snapshot *b, Snapshot *a, Snapshot *prev) {
memcpy(b->ram, a->ram, 16);
b->ram[0xfa1] = a->ram[0xfa1];
b->ram[0x72] = a->ram[0x72];
b->ram[0x73] = a->ram[0x73];
b->ram[0x74] = a->ram[0x74];
b->ram[0x75] = a->ram[0x75];
b->ram[0xb7] = a->ram[0xb7];
b->ram[0xb8] = a->ram[0xb8];
b->ram[0xb9] = a->ram[0xb9];
b->ram[0xba] = a->ram[0xba];
b->ram[0xbb] = a->ram[0xbb];
b->ram[0xbd] = a->ram[0xbd];
b->ram[0xbe] = a->ram[0xbe];
b->ram[0xc8] = a->ram[0xc8];
b->ram[0xc9] = a->ram[0xc9];
b->ram[0xca] = a->ram[0xca];
b->ram[0xcb] = a->ram[0xcb];
b->ram[0xcc] = a->ram[0xcc];
b->ram[0xcd] = a->ram[0xcd];
b->ram[0xa0] = a->ram[0xa0];
b->ram[0x128] = a->ram[0x128]; // irq_flag
b->ram[0x463] = a->ram[0x463]; // which_staircase_index_padding
// c code is authoritative
WORD(a->ram[0x1f0a]) = WORD(b->ram[0x1f0a]);
memcpy(&b->ram[0x1f0d], &a->ram[0x1f0d], 0x3f - 0xd);
memcpy(b->ram + 0x138, a->ram + 0x138, 256 - 0x38); // copy the stack over
memcpy(a->ram + 0x1DBA0, b->ram + 0x1DBA0, 240 * 2); // hdma_table
memcpy(b->ram + 0x1B00, b->ram + 0x1DBA0, 224 * 2); // hdma_table (partial)
memcpy(a->ram + 0x1cc0, b->ram + 0x1cc0, 2); // some leftover stuff in hdma table
if (memcmp(b->ram, a->ram, 0x20000)) {
fprintf(stderr, "@%d: Memory compare failed (mine != theirs, prev):\n", frame_counter);
int j = 0;
for (size_t i = 0; i < 0x20000; i++) {
if (a->ram[i] != b->ram[i]) {
if (++j < 128) {
if ((i&1) == 0 && a->ram[i + 1] != b->ram[i + 1]) {
fprintf(stderr, "0x%.6X: %.4X != %.4X (%.4X)\n", (int)i,
WORD(b->ram[i]), WORD(a->ram[i]), WORD(prev->ram[i]));
i++, j++;
} else {
fprintf(stderr, "0x%.6X: %.2X != %.2X (%.2X)\n", (int)i, b->ram[i], a->ram[i], prev->ram[i]);
}
}
}
}
if (j)
g_fail = true;
fprintf(stderr, " total of %d failed bytes\n", (int)j);
}
if (memcmp(b->sram, a->sram, 0x2000)) {
fprintf(stderr, "@%d: SRAM compare failed (mine != theirs, prev):\n", frame_counter);
int j = 0;
for (size_t i = 0; i < 0x2000; i++) {
if (a->sram[i] != b->sram[i]) {
if (++j < 128) {
if ((i&1) == 0 && a->sram[i + 1] != b->sram[i + 1]) {
fprintf(stderr, "0x%.6X: %.4X != %.4X (%.4X)\n", (int)i,
WORD(b->sram[i]), WORD(a->sram[i]), WORD(prev->sram[i]));
i++, j++;
} else {
fprintf(stderr, "0x%.6X: %.2X != %.2X (%.2X)\n", (int)i, b->sram[i], a->sram[i], prev->sram[i]);
}
}
}
}
if (j)
g_fail = true;
fprintf(stderr, " total of %d failed bytes\n", (int)j);
}
if (memcmp(b->vram, a->vram, sizeof(uint16) * 0x8000)) {
fprintf(stderr, "@%d: VRAM compare failed (mine != theirs, prev):\n", frame_counter);
for (size_t i = 0, j = 0; i < 0x8000; i++) {
if (a->vram[i] != b->vram[i]) {
fprintf(stderr, "0x%.6X: %.4X != %.4X (%.4X)\n", (int)i, b->vram[i], a->vram[i], prev->vram[i]);
g_fail = true;
if (++j >= 16)
break;
}
}
}
}
static uint8_t *RomByte(Cart *cart, uint32_t addr) {
return &cart->rom[(((addr >> 16) << 15) | (addr & 0x7fff)) & (cart->romSize - 1)];
}
bool g_calling_asm_from_c;
void HookedFunctionRts(int is_long) {
if (g_calling_asm_from_c) {
g_calling_asm_from_c = false;
return;
}
assert(0);
}
void RunEmulatedFunc(uint32 pc, uint16 a, uint16 x, uint16 y, bool mf, bool xf, int b, int whatflags) {
g_snes->debug_cycles = 1;
RunEmulatedFuncSilent(pc, a, x, y, mf, xf, b, whatflags | 2);
g_snes->debug_cycles = 0;
}
void RunEmulatedFuncSilent(uint32 pc, uint16 a, uint16 x, uint16 y, bool mf, bool xf, int b, int whatflags) {
uint16 org_sp = g_cpu->sp;
uint16 org_pc = g_cpu->pc;
uint8 org_b = g_cpu->db;
uint8 org_dp = g_cpu->dp;
if (b != -1)
g_cpu->db = b >= 0 ? b : pc >> 16;
if (b == -3)
g_cpu->dp = 0x1f00;
static uint8 *rambak;
if (rambak == 0) rambak = (uint8 *)malloc(0x20000);
memcpy(rambak, g_emulated_ram, 0x20000);
memcpy(g_emulated_ram, g_ram, 0x20000);
if (whatflags & 2)
g_emulated_ram[0x1ffff] = 0x67;
g_cpu->a = a;
g_cpu->x = x;
g_cpu->y = y;
g_cpu->spBreakpoint = g_cpu->sp;
g_cpu->k = (pc >> 16);
g_cpu->pc = (pc & 0xffff);
g_cpu->mf = mf;
g_cpu->xf = xf;
g_calling_asm_from_c = true;
while (g_calling_asm_from_c) {
if (g_snes->debug_cycles) {
char line[80];
getProcessorStateCpu(g_snes, line);
puts(line);
}
cpu_runOpcode(g_cpu);
while (g_snes->dma->dmaBusy)
dma_doDma(g_snes->dma);
if (whatflags & 1) {
/* if (apu_debugging == 2 && g_snes->apu->cpuCyclesLeft == 0) {
char line[80];
getProcessorStateSpc(g_snes->apu, line);
puts(line);
}*/
// apu_cycle(g_snes->apu);
}
}
g_cpu->dp = org_dp;
g_cpu->sp = org_sp;
g_cpu->db = org_b;
g_cpu->pc = org_pc;
memcpy(g_ram, g_emulated_ram, 0x20000);
memcpy(g_emulated_ram, rambak, 0x20000);
}
void RunOrigAsmCodeOneLoop(Snes *snes) {
Cpu *cpu = snes->cpu;
cpu->a = cpu->x = cpu->y = 0;
cpu->e = false;
cpu->irqWanted = cpu->nmiWanted = cpu->waiting = cpu->stopped = 0;
cpu_setFlags(cpu, 0x30);
// Run until the wait loop in Interrupt_Reset,
// Or the polyhedral main function.
for(int loops = 0;;loops++) {
snes_printCpuLine(snes);
cpu_runOpcode(snes->cpu);
while (snes->dma->dmaBusy)
dma_doDma(snes->dma);
uint32_t pc = snes->cpu->k << 16 | snes->cpu->pc;
if (pc == 0x8034 || pc == 0x9f81d && loops >= 10 || pc == 0x8225 || pc == 0x82D2)
break;
}
}
static void RunEmulatedSnesFrame(Snes *snes, int run_what) {
// First call runs until init
if (snes->cpu->pc == 0x8000 && snes->cpu->k == 0) {
RunOrigAsmCodeOneLoop(snes);
g_emulated_ram[0x12] = 1;
// Fixup uninitialized variable
*(uint16*)(g_emulated_ram+0xAE0) = 0xb280;
*(uint16*)(g_emulated_ram+0xAE2) = 0xb280 + 0x60;
}
// Run poly code
if (run_what & 2) {
Cpu *cpu = snes->cpu;
cpu->sp = 0x1f3e;
cpu->pc = 0xf81d;
cpu->db = cpu->k = 9;
cpu->dp = 0x1f00;
RunOrigAsmCodeOneLoop(snes);
}
// Run main code
if (run_what & 1) {
Cpu *cpu = g_snes->cpu;
cpu->sp = 0x1ff;
cpu->pc = 0x8034;
cpu->k = cpu->dp = cpu->db = 0;
RunOrigAsmCodeOneLoop(snes);
}
snes_doAutoJoypad(snes);
// animated_tile_vram_addr uninited
if (snes->ram[0xadd] == 0)
*(uint16_t*)&snes->ram[0xadc] = 0xa680;
// In one code path flag_update_hud_in_nmi uses an undefined value
snes_write(snes, DMAP0, 0x01);
snes_write(snes, BBAD0, 0x18);
// Run NMI handler
Cpu *cpu = g_snes->cpu;
cpu->sp = 0x1ff;
cpu->pc = 0x80D9;
cpu->k = cpu->dp = cpu->db = 0;
RunOrigAsmCodeOneLoop(snes);
}
// Copy state into the emulator, we can skip dsp/apu because
// we're not emulating that.
static void EmuSynchronizeWholeState() {
memcpy(&g_snes->ppu->vram, g_zenv.ppu->vram, offsetof(Ppu, ppu2openBus) + 1 - offsetof(Ppu, vram));
memcpy(g_snes->ram, g_zenv.ram, 0x20000);
memcpy(g_snes->cart->ram, g_zenv.sram, 0x2000);
memcpy(g_snes->dma->channel, g_zenv.dma->channel, sizeof(Dma) - offsetof(Dma, channel));
// todo: this is hacky
if (animated_tile_data_src == 0)
cpu_reset(g_snes->cpu);
}
void EmuRunFrameWithCompare(uint16 input_state, int run_what) {
MakeSnapshot(&g_snapshot_before);
MakeMySnapshot(&g_snapshot_mine);
MakeSnapshot(&g_snapshot_theirs);
// Compare both snapshots before we run the frame, to see they match
VerifySnapshotsEq(&g_snapshot_mine, &g_snapshot_theirs, &g_snapshot_before);
if (g_fail) {
printf("early fail\n");
assert(0);
//return turbo;
}
// Run orig version then snapshot
again_theirs:
g_snes->input1->currentState = input_state;
RunEmulatedSnesFrame(g_snes, run_what);
MakeSnapshot(&g_snapshot_theirs);
// Run my version and snapshot
again_mine:
ZeldaRunFrameInternal(input_state, run_what);
MakeMySnapshot(&g_snapshot_mine);
// Compare both snapshots
VerifySnapshotsEq(&g_snapshot_mine, &g_snapshot_theirs, &g_snapshot_before);
if (g_fail) {
// g_fail = false;
if (1) {
RestoreMySnapshot(&g_snapshot_before);
//SaveLoadSlot(kSaveLoad_Save, 0);
if (0)
goto again_mine;
RestoreSnapshot(&g_snapshot_before);
goto again_theirs;
}
if (1) {
MakeSnapshot(&g_snapshot_theirs);
RestoreMySnapshot(&g_snapshot_theirs);
}
}
}
static void PatchRomBP(uint8_t *rom, uint32_t addr) {
rom[(addr >> 16) << 15 | (addr & 0x7fff)] = 0;
}
static void PatchRomByte(uint8_t *rom, uint32_t addr, uint8 old_value, uint8 value) {
assert(rom[(addr >> 16) << 15 | (addr & 0x7fff)] == old_value);
rom[(addr >> 16) << 15 | (addr & 0x7fff)] = value;
}
static void PatchRomWord(uint8_t *rom, uint32_t addr, uint16 old_value, uint16 value) {
assert(WORD(rom[(addr >> 16) << 15 | (addr & 0x7fff)]) == old_value);
WORD(rom[(addr >> 16) << 15 | (addr & 0x7fff)]) = value;
}
static void PatchRom(uint8_t *rom) {
// fix a bug with unitialized memory
{
uint8_t *p = rom + 0x36434;
memmove(p, p + 2, 7);
p[7] = 0xb0;
p[8] = 0x40 - 7;
}
// BufferAndBuildMap16Stripes_Y can read bad memory if int is negative
if (1) {
uint8_t *p = rom + 0x10000 - 0x8000;
int thunk = 0xFF6E;
uint8_t *tp = p + thunk;
*tp++ = 0xc0; *tp++ = 0x00; *tp++ = 0x20;
*tp++ = 0x90; *tp++ = 0x03;
*tp++ = 0xa9; *tp++ = 0x00; *tp++ = 0x00;
*tp++ = 0x9d; *tp++ = 0x00; *tp++ = 0x05;
*tp++ = 0x60;
p[0xf4a7] = 0x20; p[0xf4a8] = thunk; p[0xf4a9] = thunk >> 8;
p[0xf4b5] = 0x20; p[0xf4b6] = thunk; p[0xf4b7] = thunk >> 8;
p[0xf3dd] = 0x20; p[0xf3de] = thunk; p[0xf3df] = thunk >> 8;
p[0xf3ef] = 0x20; p[0xf3f0] = thunk; p[0xf3f1] = thunk >> 8;
}
// Better random numbers
if (1) {
// 8D:FFC1 new_random_gen:
int new_routine = 0xffc1;
uint8_t *p = rom + 0x60000, *tp = p + new_routine;
*tp++ = 0xad; *tp++ = 0xa1; *tp++ = 0x0f; // mov.b A, byte_7E0FA1
*tp++ = 0x18; *tp++ = 0x65; *tp++ = 0x1a; // add.b A, frame_counter
*tp++ = 0x4a; // lsr A
*tp++ = 0xb0; *tp++ = 0x02; // jnb loc_8DFFCC
*tp++ = 0x49; *tp++ = 0xb8; // eor.b A, #0xB8
*tp++ = 0x8d; *tp++ = 0xa1; *tp++ = 0x0f; // byte_7E0FA1, A
*tp++ = 0x18; // clc
*tp++ = 0x6b; // retf
p[0xBA71] = 0x4c; p[0xBA72] = new_routine; p[0xBA73] = new_routine >> 8;
}
{
}
// Fix so SmashRockPile_fromLift / Overworld_DoMapUpdate32x32_B preserves R2/R0 destroyed
{
/*
.9B:BFA2 A5 00 mov.w A, R0
.9B:BFA4 48 push A
.9B:BFA5 A5 02 mov.w A, R2
.9B:BFA7 48 push A
.9B:C0F1 22 5C AD 02 callf Overworld_DoMapUpdate32x32_B
.9B:C048 68 pop A
.9B:C049 85 00 mov.w R0, A
.9B:C04B 68 pop A
.9B:C04C 85 02 mov.w R2, A
*/
uint8_t *tp = rom + 0x6ffd8;
*tp++ = 0xa5; *tp++ = 0x00; *tp++ = 0x48;
*tp++ = 0xa5; *tp++ = 0x02; *tp++ = 0x48;
*tp++ = 0x22; *tp++ = 0x5c; *tp++ = 0xad; *tp++ = 0x02;
*tp++ = 0xc2; *tp++ = 0x30;
*tp++ = 0x68; *tp++ = 0x85; *tp++ = 0x02;
*tp++ = 0x68; *tp++ = 0x85; *tp++ = 0x00;
*tp++ = 0x6b;
int target = 0xDFFD8; // DoorAnim_DoWork2_Preserving
rom[0xdc0f2] = target;
rom[0xdc0f3] = target >> 8;
rom[0xdc0f4] = target >> 16;
}
rom[0x2dec7] = 0; // Fix Uncle_Embark reading bad ram
rom[0x4be5e] = 0; // Overlord05_FallingStalfos doesn't initialize the sprite_D memory location
rom[0xD79A4] = 0; // 0x1AF9A4: // Lanmola_SpawnShrapnel uses undefined carry value
rom[0xF0A46] = 0; // 0x1E8A46 Helmasaur Carry Junk
rom[0xF0A52] = 0; // 0x1E8A52 Helmasaur Carry Junk
rom[0xef9b9] = 0xb9; // TalkingTree_SpitBomb
rom[0xdf107] = 0xa2;
rom[0xdf108] = 0x03;
rom[0xdf109] = 0x6b; // Palette_AgahnimClone destoys X
rom[0x4a966] = 0; // Follower_AnimateMovement_preserved
PatchRomBP(rom, 0x1de0e5);
PatchRomBP(rom, 0x6d0b6);
PatchRomBP(rom, 0x6d0c6);
PatchRomBP(rom, 0x1d8f29); // adc instead of add
PatchRomBP(rom, 0x06ED0B);
PatchRomBP(rom, 0x1dc812); // adc instead of add
PatchRomBP(rom, 0x9b46c); // adc instead of add
PatchRomBP(rom, 0x9b478); // adc instead of add
PatchRomBP(rom, 0x9B468); // sbc
PatchRomBP(rom, 0x9B46A);
PatchRomBP(rom, 0x9B474);
PatchRomBP(rom, 0x9B476);
PatchRomBP(rom, 0x9B60C);
PatchRomBP(rom, 0x8f708); // don't init scratch_c
PatchRomBP(rom, 0x1DCDEB); // y is destroyed earlier, restore it..
// Smithy_Frog doesn't save X
memmove(rom + 0x332b8, rom + 0x332b7, 4); rom[0x332b7] = 0xfa;
// This needs to be here because the ancilla code reads
// from the apu and we don't want to make the core code
// dependent on the apu timings, so relocated this value
// to 0x648.
rom[0x443fe] = 0x48; rom[0x443ff] = 0x6;
rom[0x44607] = 0x48; rom[0x44608] = 0x6;
// AncillaAdd_AddAncilla_Bank09 destroys R14
rom[0x49d0c] = 0xda; rom[0x49d0d] = 0xfa;
rom[0x49d0f] = 0xda; rom[0x49d10] = 0xfa;
// Prevent LoadSongBank from executing in the rom because it hangs
rom[0x888] = 0x60;
// CleanUpAndPrepDesertPrayerHDMA clearing too much
PatchRomWord(rom, 0x2C7E5 + 1, 0x1df, 0x1cf);
// Merge ancilla_arr23 with boomerang_arr1 because they're only 3 bytes long,
// and boomerang might get allocated in slot 4.
PatchRomByte(rom, 0x9816C, 0xd2, 0xCF);
PatchRomByte(rom, 0xffdeb, 0xd2, 0xCF);
PatchRomByte(rom, 0xffdee, 0xd2, 0xCF);
PatchRomByte(rom, 0xffdf7, 0xd2, 0xCF);
PatchRomByte(rom, 0xffdfa, 0xd2, 0xCF);
// Relocate the door debris variables so they become 5 entries each (they were 2 before).
static const int kDoorDebrisX_Uses[] = {0x1CFC6, 0x1d29d, 0x89794, 0x897a3, 0x8a0a1, 0x8edca, 0x99aa6};
for (int i = 0; i < countof(kDoorDebrisX_Uses); i++) PatchRomWord(rom, kDoorDebrisX_Uses[i] + 1, 0x3b6, 0x728);
static const int kDoorDebrisX1_Uses[] = { 0x89797, 0x897A6 };
for (int i = 0; i < countof(kDoorDebrisX1_Uses); i++) PatchRomWord(rom, kDoorDebrisX1_Uses[i] + 1, 0x3b7, 0x729);
static const int kDoorDebrisY_Uses[] = { 0x1CFD7, 0x1D2AE, 0x8A099, 0x8EDC5, 0x99AA1 };
for (int i = 0; i < countof(kDoorDebrisY_Uses); i++) PatchRomWord(rom, kDoorDebrisY_Uses[i] + 1, 0x3ba, 0x732);
static const int kDoorDebrisDir_Uses[] = { 0x1CFB2, 0x1D2BA, 0x8A0B7 };
for (int i = 0; i < countof(kDoorDebrisDir_Uses); i++) PatchRomWord(rom, kDoorDebrisDir_Uses[i] + 1, 0x3be, 0x73c);
static const int ancilla_arr26_Uses[] = { 0x89fb9, 0x89fc0, 0x98157, 0x99c49 };
for (int i = 0; i < countof(ancilla_arr26_Uses); i++) PatchRomWord(rom, ancilla_arr26_Uses[i] + 1, 0x3c0, 0x741);
static const int ancilla_arr25_Uses[] = { 0x89fc3, 0x89fc6, 0x8a0ae, 0x8ab7c, 0x8aba7, 0x8abb6, 0x8ae92, 0x8bae2, 0x8baff, 0x8f429, 0x98148, 0x98e0a, 0x98ebc, 0x9920a, 0x9931e, 0x9987f, 0x99c44 };
for (int i = 0; i < countof(ancilla_arr25_Uses); i++) PatchRomWord(rom, ancilla_arr25_Uses[i] + 1, 0x3c2, 0x746);
static const int ancilla_arr22_Uses[] = { 0x9816e, 0xffde0, 0xffde7 };
for (int i = 0; i < countof(ancilla_arr22_Uses); i++) PatchRomWord(rom, ancilla_arr22_Uses[i] + 1, 0x3e1, 0x74b);
PatchRomWord(rom, 0xddfac + 1, 0xfa85, 0xfa70); // call Hud_Rebuild instead of Hud_UpdateOnly
}
bool EmuInitialize(uint8 *data, size_t size) {
PatchRom(data);
g_snes = snes_init(g_emulated_ram);
g_cpu = g_snes->cpu;
ZeldaSetupEmuCallbacks(g_emulated_ram, &EmuRunFrameWithCompare, &EmuSynchronizeWholeState);
return snes_loadRom(g_snes, data, (int)size);
}